Type of the light source. This value is one of the members of the D3DLIGHTTYPE enumerated type.

Diffuse

Diffuse color emitted by the light. This member is a D3DCOLORVALUE structure.

Specular

Specular color emitted by the light. This member is a D3DCOLORVALUE structure.

Ambient

Ambient color emitted by the light. This member is a D3DCOLORVALUE structure.

Position

Position of the light in world space, specified by a D3DVECTOR structure. This member has no meaning for directional lights and is ignored in that case.

Direction

Direction that the light is pointing in world space, specified by a D3DVECTOR structure. This member has meaning only for directional and spotlights. This vector need not be normalized, but it should have a nonzero length.

Range

Distance beyond which the light has no effect. The maximum allowable value for this member is the square root of FLT_MAX. This member does not affect directional lights.

Falloff

Decrease in illumination between a spotlight's inner cone (the angle specified by
Theta) and the outer edge of the outer cone (the angle specified by Phi).

The effect of falloff on the lighting is subtle. Furthermore, a small performance penalty is incurred by shaping the falloff curve. For these reasons, most developers set this value to 1.0.

Attenuation0

Value specifying how the light intensity changes over distance. Attenuation values are ignored for directional lights. This member represents an attenuation constant. For information about attenuation, see Light Position, Range, and Attenuation. Valid values for this member range from 0.0 to infinity. For non-directional lights, all three attenuation values should not be set to 0.0 at the same time.

Attenuation1

Value specifying how the light intensity changes over distance. Attenuation values are ignored for directional lights. This member represents an attenuation constant. For information about attenuation, see Light Position, Range, and Attenuation. Valid values for this member range from 0.0 to infinity. For non-directional lights, all three attenuation values should not be set to 0.0 at the same time.

Attenuation2

Value specifying how the light intensity changes over distance. Attenuation values are ignored for directional lights. This member represents an attenuation constant. For information about attenuation, see Light Position, Range, and Attenuation. Valid values for this member range from 0.0 to infinity. For non-directional lights, all three attenuation values should not be set to 0.0 at the same time.

Theta

Angle, in radians, of a spotlight's inner cone—that is, the fully illuminated spotlight cone. This value must be in the range from 0 through the value specified by Phi.

Phi

Angle, in radians, defining the outer edge of the spotlight's outer cone. Points outside this cone are not lit by the spotlight. This value must be between 0 and pi.